This invention relates to shaft mounted drive components, and more particularly, this invention relates to a shaft mounted cluster roller assembly used in material handling applications.
Cluster roller assemblies are used in container translating and orienting apparatus, such as disclosed in U.S. Pat. Nos. 4,981,209 and 5,064,045 assigned to FMC Corporation, the disclosures which are hereby incorporated by reference in their entirety. In these types of apparatus, the movement of flat bottomed articles is controlled in a plurality of different directions relative to a supporting platform. The article is supported on a plurality of clusters of helically mounted, freely rotatable rollers mounted on a plurality of shafts. The different shafts or groups of shafts lie in one of a plurality of zones and are selectively driven in a clockwise direction, a counter-clockwise direction, or held stationary. Selective control of various drive shafts enables the apparatus to move an article parallel to the longitudinal axis of the platform in two selected directions, perpendicular to the longitudinal axis in two selected directions, diagonally of the longitudinal axis in four selected directions, and either clockwise or counter-clockwise about an axis normal to the flat bottom of the article.
About one-half to one percent of all cluster roller assemblies will eventually require field replacement because of collisions with fork lift tines, damaged Unit Load Devices (ULD""s) or an inherent manufacturing defect. Typically, the cluster roller assemblies are formed as one-piece, integrally cast, aluminum support or body members having a central hub and peripheral end flanges with support legs that support rollers at roller support positions defined by the support legs along the periphery.
The rollers are set at an angle of about 45xc2x0 relative to a central axis defined by an opening within the hub of the support member. A drive shaft is received through the openings, and a locking pin or drive pin supported by the drive shaft engages the support member and retains the support member in position on the drive shaft. The conveyor includes walk plates, drive shafts, chains, bearings, tensioners, drive pins, and adjacent cluster roller assemblies on the same drive shaft that have to be removed to obtain access to the broken cluster roller assembly.
Each component must then be reinstalled and the chains tensioned. This process can take hours for a one casting replacement, i.e., cluster roller assembly replacement. As a result, many cluster roller assemblies are not repaired. Also, because of the severe stresses involved, prior art techniques have not always been advantageous, such as splitting the cluster roller assembly along the hub. Even if a cluster roller assembly is split along the hub, the hub would still have to be slid onto a drive shaft, as compared to a cluster roller assembly that was split, such as by sawing, along a central axis defined by the opening that receives a drive shaft. However, when an integrally cast, one-piece support member is split in half, then the alignment and positioning of the half members and rollers is no longer maintained unless additional components or methods are used to maintain the alignment and positioning. For example, a saw kerf would remove some small amount of material, but that material loss would be enough to lose the accuracy and alignment of the rollers, support legs and other components.
The present invention is advantageous and now permits a shaft mounted drive component to be readily replaced onto a drive shaft or other shaft by placing two split half members and laterally moving them together over the shaft and securing the members together. Alignment and positioning is maintained.
In one aspect of the present invention, a shaft mounted drive component includes a body member having first and second half members and an opening defining a central axis through which a shaft is received for mounting the body member on the shaft. The first and second half members are divided by a gap, such as produced by sawing and forming a gap along the central axis. The body member has a plurality of alignment holes split by the cut. A spacer pin is received within each alignment hole and is substantially the same diameter as each alignment hole. The spacer pin also has a diameter larger than the formed gap to maintain alignment and positioning of the half members and rollers as before splitting and facilitating replacement of first and second half members on a shaft.
In another aspect of the present invention, the body member forms a cluster roller assembly and includes a plurality of rollers mounted thereon and disposed at an acute angle relative to the axis of rotation. The body member also includes a circumferential periphery having roll support positions at which the rollers are supported. At least one fastener retains the first and second half members together. The fastener can be ring-shaped and positioned adjacent the opening through which a shaft is received.
In yet another aspect of the present invention, a conveyor permits selective translation or rotation of a flat bottomed article and includes a frame and a plurality of drive shafts rotatably mounted on the frame and positioned substantially parallel to each other. Each drive shaft includes a plurality of cluster roller assemblies mounted thereon. Each cluster roller assembly has a plurality of rollers rotatably mounted along the periphery and disposed at an acute angle relative to the axis of rotation. The cluster roller assemblies each comprise a roller support member having an opening defining a central axis through which a drive shaft is received, and peripheral roller support positions where the rollers are mounted. The roller support member further comprises first and second half members divided along the central axis. At least one fastener retains first and second roller support members together. A motor is connected to rotatably drive each support shaft in both directions.
An end pin acts as a locking or drive pin and interconnects each cluster roller assembly and drive shaft for locking the cluster roller assembly in a predetermined position on the drive shaft. Each roller support member is split into first and second half members by the cut and includes a plurality of alignment holes split by the cut. A spacer pin is received within each alignment hole and is substantially the same diameter and has a diameter larger than the gap formed by the cut or xe2x80x9ckerfxe2x80x9d to maintain alignment and positioning of the half members and rollers. A controller can be connected to the motor for causing the motor to rotate in a desired direction so that an article is translated in a desired direction to the drive shafts. Walk plates define a planar surface and a portion of the cluster roller assemblies extend upward beyond the walk plates to engage an article.
In yet another aspect of the present invention, a method is disclosed of forming a drive component for ready replacement onto a shaft and maintaining the positioning of the drive component and associated parts. The method comprises the step of providing an integral one-piece body member having an opening that defines a central axis through which a shaft is received. A plurality of alignment holes are drilled into the body member in a coplanar configuration and aligned with the central axis. The body member is divided via a cut along the opening and through the alignment holes into first and second half members. During replacement, the half members are aligned along the drive shaft and spacer pins are inserted within each alignment hole. Each spacer pin has the same diameter as the alignment hole and is greater in diameter than the width of the gap formed by the cut, i.e., material that has been removed, to maintain alignment and positioning of the first and second half members and rollers as before splitting. The half members are then secured together, such as by ring fastener.